UltraStar Play

UltraStar Play is a free and open-source karaoke party game for Windows. Players sing along to their favorite songs while the game displays lyrics, notes, and optional background videos or images, scoring performances based on pitch and timing. It supports solo play, duets, groups, cooperative scoring, custom songs, playlists, medleys, a built-in song editor, and a companion app that can turn a smartphone into a microphone.